Polymer-based membrane mirrors for micro-optical sensors

We present the first use of polymer technology for the fabrication of deformable micro-mirrors. A self-supporting membrane fabricated using SU-8, with a diameter of 1 mm and a thickness of less than 10 μm, can be used as either an active or passive optical component in a sensor system. In combination with an electrode array beneath the membrane, electrostatic actuation is used to deform the mirror for adaptive optics applications useful in, for example, wavefront formation or 2D-scanners for bio-chip readers. The described technology can also be used to produce other types of membrane devices such as pressure sensors, pumps or valves. The mechanical properties of the SU-8 polymer are such that the forces required for deflection are reduced, thus increasing mirror flexibility and sensitivity, but the fabrication process is simple and potentially low cost.